Today is our 4th
working dayon board the R/V
Philia, the research vessel of the Hellenic Centre for Marine Research. We are in
the harbour of Kerkyra (Corfu) and waiting for better weather – deploying ROVs
at 7 or 8 Beaufort is not an option.

For me, the trip
started very early on Friday March 8, leaving Aberdeen Airport for Amsterdam
and Athens. I spent the evening with Kostas Tsiamis and family in his new home
in Palio Faliro, and the next day visiting my old friends in the same seaside
neighbourhood of Athens which is the home to many childhood memories for me.

Early on Sunday
morning, we met up with Panayotis (Panos) Panayotidis and the two ROV pilots,
Leonidas Manousakis and Manolis Kaleris, who had arrived in Athens by plane
from their base in Heraklion. We drove to Patras, visiting our dear friend
Christos Katsaros and his wife “Mama” Efi in their country house in Derveni (on
the southern shore of the Gulf of Korinth, at this time of the year with the
spectacular scenery of snow-covered Parnassos in the background) on the way. In
the port of Patras, the R/V Philia was waiting for us. We boarded and
immediately set sail for Argostoli, the capital of Kefalonia. The vessel did
not sail very fast, it took us around 5 hours to get there (compared to around
3 h for a typical ferry).

Kelp in Greek waters?

The purpose of our
research cruise is to explore the poorly-known deep water seaweed flora of the
Ionian Sea. In particular, we are in search of the kelp Laminaria rodriguezii. Kelps are large brown algae forming forest-like
communities on the seabed, mostly known from cold seas. In fact, their
distribution is limited by an upper lethal temperature, typically in the range
of 17-20°C. Having or not having kelp in an area of seabed is a major difference
for a lot of other life forms – like the difference between a forest or a
meadow on land. While winter temperatures in the Mediterranean are comparable
to the temperate North Atlantic (10-15°C), in the summer they can rise to
25-30°C – like a tropical sea. Only a limited number of species can withstand
such extreme fluctuations, which are a peculiar feature of the Mediterranean
marine ecosystem.Such conditions are
definitely not suitable for kelps!

However, this applies
mostly to surface waters – to the first couple of tens of metres, down to the
thermocline (de facto a horizontal boundary, beneath which the temperature
suddenly declines, typically to something less than 15 -17 °C). Much of the
Mediterranean has very transparent waters, enabling enough light penetration to
sustain algal growth at much greater depths than e.g. on North Atlantic coasts.
In such waters, seaweeds can grow at depths exceeding 100 m. Thus, there is
potential for cold-water communities to survive in deeper layers of the
Mediterranean. In fact, our California-based collaborator Mike Graham has
developed a computer model using hydrographic data (chiefly temperature and
water transparency) for predicting the likelihood of finding suitable kelp
habitat in the warmer parts of our Ocean Planet. Indeed, one species of
deep-water kelp is known from the Western Mediterranean – Laminaria rodriguezii. It grows for example in the Straits of
Messina or the central Adriatic at depths of around and beneath 70 m. Still,
much of its biology remains enigmatic – and, again, the existence or absence of
kelp makes a big difference to the wider seabed communities. Enough good
reasons to search for kelp in the Eastern Mediterranean!

Around much of Greece,
the thermocline is typically around 40-50 m. Accessing such depths by scuba
diving (and to do any scientific work there) is quite a challenge if not
impossible. In such cases, marine scientists rely on technology to do the job –
Remotely Operated Vehicles (ROVs), i.e. underwater robots, or even manned
submersibles. The Hellenic Centre for Marine Research has both options
available, but using its manned submersible THETIS requires the largest (and
most expensive) research vessel, AEGAEO as platform. For this cruise, we went
for the next smaller option, the R/V Philia with 2 ROVs, Seaeye Falcon andLBV200e Seabotix.

The F/R PHILIA, built at Piraeus (1985),
commissioned in 1986, operates from her home port of Irakleion, not only in
Cretan waters, but also throughout the Aegean and Ionian. The vessel is 26.1 m
long and has a gross tonnage of 143 tons.

The PHILIA's greatest asset is her
flexibility, she is large enough to operate offshore but because of her shallow
draft she can also operate close inshore.

She has covered many thousands of miles
carrying out research and in 1997 was refitted with a bulbous bow and a second
engine as part of the Greek Government's commitment to marine science research.

Kefalonia,
March 11

A beautiful morning greeted us in the
harbor of Argostoli, Kefalonia’s capital. The R/V Philia soon set sail for the
narrows between Kefalonia and Zakynthos for the first ROV dives of the cruise.
Kostas and I donned our dive suits and boarded a dinghy with outboard engine
for surveying 2 sites of the national marine environmental monitoring program
in southern Kefalonia. The first site yielded a new record for Greek waters, Dictyota cyanoloma.

Dictyota
cyanoloma, new record for Greece

Cruising
the waters off southern Kefalonia in search of suitable dive sites

Nudibranch
and coralline red algae, southern Kefalonia

Asparagopsis
and coralline red algae, southern Kefalonia

Seascape,
southern Kefalonia

The
two ROV pilots, Manolis (l) and Leonidas (r), and a crew member of the Philia
(center)

Leonidas
and the smaller of the 2 ROVs

We returned to the Philia, where ROV work
had started. Two ROV dives were conducted, running transects from around 120 to
50 m depths and yielding some excellent footage. No Laminaria though…

After a long day, we sailed into the port
of Sami on Kefalonia’s east side where we moored for the night.

(LeonidasManousakis)

Δουλεύαμε με το μικρό μας(LBV200eSeabotix), αλλά μιά βλάβη
μας αναγκάζει να ετοιμάσουμε το μεγαλύτερό (SeaeyeFalcon) και να συνεχίσουμε την έρευνα του βυθού. We started to work with our small ROV ( LBV200e Seabotix), but a
problem in one of the thrusters make us to continue the the sea bottom search
with our our medium one (Seaeye Falcon).

Μόλις δέσαμε στην περιοχή της Σαμις, όπου θα περάσουμε και το βράδυ. We have just get to the port of Sami, where we will spend the night.

Kefalonia
and Ithaca – Tuesday, March 12, 2013

(Frithjof)

Today, we set sail out
of Sami into the sea straits between Kefalonia and Ithaca, the mythical home
island of Odysseus. Same procedure as yesterday – Kostas and I were taken by
dinghy to an inshore sampling site, while the remainder of the crew started ROV
work. The crystal-clear waters of the Ionian Sea are legendary. What else in
the world could be better now, snorkelling in the turquoise waters of Kefalonia
with visibility of 50 m of higher, with olive groves on the shore… and winter
still at home in Aberdeenshire. Again a large number of seaweed taxa collected,
plus some great underwater photography. We visited a second sampling site, a
tiny islet with a bird colony in the middle of the straits. The high water
transparency is the result of ultra-oligotrophic conditions, i.e. extremely low
nutrient levels – de facto, the Ionian Sea (and the southern Aegean and
Levantine Seas) are low-productivity marine desert regions.

The crystal-clear, blue waters of the Ionian Sea...

We managed to conduct an
ROV dive, down to around 95 m – but still no Laminaria!

In the afternoon, we
had a rough crossing to the remote small islands of Paxi (Πάξοι), just south of
Kerkyra (Corfu) which took us around 5 h.

The capital of this small archipelago,
Gaios, is very scenically located in a sheltered inlet on the east side of the
main island, Paxos. We went ashore for a stroll around that picturesque little
town, to a kafeneion and then for dinner in a local tavern. We were met by
Babis (Charalambos), a former student of Panos and now owner of a dive centre,
and spent a very pleasant evening together.

This morning, we
managed to conduct a total of 5 ROV dives, the most in a single day so far,
down to 80 m, in the sea area east of Paxoi / SE of Kerkyra. According to Mike
Graham’s computer-generated prediction map, this is a high-probability area for
the occurrence of Laminaria. Still… no luck! All the seabed (benthos) that we
encountered today was very soft sediment, not suitable for kelp.

One
of the most iconic images of Greece, and scenic even under a cloudy sky…

Dinner and
Cretan raki on the Philia

In the Ionian Sea north of Kerkyra –
Friday, March 15, 2013

(Leonidas
Manousakis)

Ο καιρός είναι λίγο καλύτερα. Θα προσπαθήσουμε να δουλέψουμε στον κόλπο της
Κερκυρας. Βγαίνουμε από το λιμάνι. The weather is a bit
better. We will try to work on Corfu's bay. Getting out of the harbour.

Kerkyra

Othonoi
Islands – Friday, March 15, 2013

(Leonidas
Manousakis)

Το πλοίο ταξίδευε από το πρωί και στις 10.00 πμ είμαστε στα νησιά Οθωνοί.
Το βορειότερο ακρο της Ελάδας στην Αδριατικη. Θα δουλέψουμε όπως μπορούμε μιά
και τα κύμματα είναι ακόμη αρκετά μεγάλα για να είμαστε στα ανοικτά. Το πλοίο
έχει ποντίση μία αγκυρα από την πρύμη, ώστε να μπορεί να
κρατηθεί. The ship has been travelling since 7 am this
morning and at 10.00 am we are now at the Othonoi Island. These islands are the
northernmost part of Greece in the Adriatic Sea. We will try to work as well as
possible because the sea conditions are not the best.

Ereikoussa Island, March 15, 2013

Heading back into the harbor of
Kerkyra - March 15, 2013

(Leonidas
Manousakis)

Κάναμε δύο βουτιές βόρεια της Κερκυρας, λίγο μετά την είσοδου του διαυλου.
Ο βυθός εβρυθε από ζωή, αλλά τα ρευματα στην επιφάνεια του βυθού ήταν πολύ
ισχυρά. Τώρα έχουμε πορεία για το λιμάνη της Κέρκυρας, όπου θα
διανυκτερευσουμε. We have done two dives, north of Corfu Island, near
the canal between Greece and Albania. The seabed was very interesting, full of
life, but with strong water current. Now we are going to the Corfu's harbor,
where we will spend the night.

Στην Ηγουμενίτσα παρακολουθήσαμε την Αποκριάτικη παρελαση. When we were in the city of Igoumenitsa, we watched the carnival
parade.

Carnival
in Igoumenitsa, March 16

Arrived
in the port of Igoumenitsa

Heading back to Crete from Kerkyra -
March 17, 2013

(LeonidasManousakis)

Το πρωί μας βρίσκει στο λιμάνι της Κερκυρας, όπου και κατεβαίνουμε από το
πλοίο, για να πάρουμε το αεροπλάνο για Ηράκλειο. Το πλοίο θα συνεχίσει την
δουλειά στην περιοχή με αλλη ομάδα, που ήρθε σήμερα. We are at the Corfu's harbor in
the morning, in order to get into the flight to Herakleio. The Ship will
continue to work in the area, with another scientific group, that came today.

The trip back from Igoumenitsa to Athens –
March 17, 2013

(Frithjof)

This was the time to say goodbye.
An HCMR staff member had come from Athens to pick us up from Igoumenitsa and
for driving us back to Athens. A very scenic drive indeed, under a cloudless
sky and beneath snow-covered mountains, often with spring blossom, lakes and
dark-blue inlets of the sea in the foreground. Unforgettable. From Igoumenitsa
to Ioannina, and on to Arta, Amfilochia, then to the bridge from Antirrio to
Rio, and along the south shore of the Gulf of Korinth to the Greek capital, in
around 7 h in total.

Even though we did not find what
we had set out for (actually this has rarely happened during my expeditions),
it was a great experience of what ROVs can accomplish in exploring
circalittoral habitats which cannot easily be reached by scuba diving. We
clearly needed more ROV dive time for having a decent chance of finding what we
were looking for – which means working in more stable weather. Also, the
computer-generated prediction model could do with some more, high-resolution
refining.

We are now planning on a
follow-up cruise in October, when weather conditions should be a lot more
stable than around the spring equinoxes.